There are some things that have a great impact on the performance of your espresso machine. One of which is the watts and boiler size of your machine.
In order get the maximum performance out of any machine you make sure that you have the proper voltage and amperage. Lets say for example you have a 240 volt rated 3600 watt espresso machine but you only have 208 volts at your outlet. You will not get the full benefit of the watts until you reach the 240 volts the watts go down as the volts go down. The same thing applies for 120 volts as opposed to 105 volts.
One solution is to have your electrician install a step up transformer or buck booster as its called to get the most volts. Another solution is to upgrade your heating element to a larger size. Make sure you consult with a licensed bonded electrician before making any decisions on this matter.